A SpaceX statement sent to CNBC said a "preliminary review of the data and debris suggests a breach in the second stage's helium system" on the Falcon 9, "but the cause of the breach is still unknown."

According to The Washington Post, SpaceX investigators noticed "an odd shadow and then a white spot" on the roof of a nearby building that belongs to a competitor, part of a "bizarre twist" that suggests SpaceX is considering sabotage a possible cause of the explosion.

Watch: SpaceX Rocket Explodes on Launch Pad During Test

A massive explosion erupted Sept. 1, 2016, at SpaceX's main launch pad, destroying a rocket as well as a satellite that Facebook was counting on to spread internet service in Africa. (Published Friday, Sept. 2, 2016)